Forty-eight hours of postoperative pain relief after total hip arthroplasty with a novel, extended-release epidural morphine formulation

Nanotechnology for Pain Management

Introduction: In the context of the current opioid crisis, non-pharmacologic approaches to pain management have been considered important alternatives to the use of opioids or analgesics. Advancements in nano and quantum technology have led to the development of several nanotransporters, including nanoparticles, micelles, quantum dots, liposomes, nanofibers, and nano-scaffolds. These modes of nanotransporters have led to the development of new drug formulations. In pain medicine, new liposome formulations led to the development of DepoFoam™ introduced by Pacira Pharmaceutical, Inc. (Parsippany, NJ, USA). This formulation is the base of DepoDur™, which comprises a combination of liposomes and extended-release morphine, and Exparel™, which comprises a combination of liposomes and extended-release bupivacaine. In 2021, Heron Therapeutics (San Diego, CA, USA) created Zynrelef™, a mixture of bupivacaine and meloxicam. Advancements in nanotechnology have led to the development of devices/patches containing millions of nanocapacitors. Data suggest that these nanotechnology-based devices/patches reduce acute and chronic pain. Methods: Google and PubMed searches were conducted to identify studies, case reports, and reviews of medical nanotechnology applications with a special focus on acute and chronic pain. This search was based on the use of keywords like nanotechnology, nano and quantum technology, nanoparticles, micelles, quantum dots, liposomes, nanofibers, nano-scaffolds, acute and chronic pain, and analgesics. This review focuses on the role of nanotechnology in acute and chronic pain. Results: (1) Nanotechnology-based transporters. DepoDur™, administered epidurally in 15, 20, or 25 mg single doses, has been demonstrated to produce significant analgesia lasting up to 48 h. Exparel™ is infiltrated at the surgical site at the recommended dose of 106 mg for bunionectomy, 266 mg for hemorrhoidectomy, 133 mg for shoulder surgery, and 266 mg for total knee arthroplasty (TKA). Exparel™ is also approved for peripheral nerve blocks, including interscalene, sciatic at the popliteal fossa, and adductor canal blocks. The injection of Exparel™ is usually preceded by an injection of plain bupivacaine to initiate analgesia before bupivacaine is released in enough quantity from the depofoarm to be pharmacodynamically effective. Finally, Zynrelef™ is applied at the surgical site during closure. It was initially approved for open inguinal hernia, abdominal surgery requiring a small-to-medium incision, foot surgery, and TKA. (2) Nanotechnology-based devices/patches. Two studies support the use of nanocapacitor-based devices/patches for the management of acute and chronic pain. A randomized study conducted on patients undergoing unilateral primary total knee (TKA) and total hip arthroplasty (THA) provided insight into the potential value of nanocapacitor-based technology for the control of postoperative acute pain. The results were based on 2 studies, one observational and one randomized. The observational study was conducted in 128 patients experiencing chronic pain for at least one year. This study suggested that compared to baseline, the application of a nanocapacitor-based Kailo™ pain relief patch on the pain site for 30 days led to a time-dependent decrease in pain and analgesic use and an increase in well-being. The randomized study compared the effects of standard of care treatment to those of the same standard of care approach plus the use of two nanocapacitor-based device/patches (NeuroCuple™ device) placed in the recovery room and kept in place for three days. The study demonstrated that the use of the two NeuroCuple™ devices was associated with a 41% reduction in pain at rest and a 52% decrease in the number of opioid refills requested by patients over the first 30 days after discharge from the hospital. Discussion: For the management of pain, the use of nano-based technology has led to the development of nano transporters, especially focus on the use of liposome and nanocapacitors. The use of liposome led to the development of DepoDur™, bupivacaine Exparel™ and a mixture of bupivacaine and meloxicam (Zynrelef™) and more recently lidocaine liposome formulation. In these cases, the technology is used to prolong the duration of action of drugs included in the preparation. Another indication of nanotechnology is the development of nanocapacitor device or patches. Although, data obtained with the use of nanocapacitors are still limited, evidence suggests that the use of nanocapacitors devices/patches may be interesting for the treatment of both acute and chronic pain, since the studies conducted with the NeuroCuple™ device and the based Kailo™ pain relief patch were not placebo-controlled, it is clear that additional placebo studies are required to confirm these preliminary results. Therefore, the development of a placebo devices/patches is necessary. Conclusions: Increasing evidence supports the concept that nanotechnology may represent a valuable tool as a drug transporter including liposomes and as a nanocapacitor-based device/patch to reduce or even eliminate the use of opioids in surgical patients. However, more studies are required to confirm this concept, especially with the use of nanotechnology incorporated in devices/patches.

Comparing pain intensity rating scales in acute postoperative pain: boundary values and category disagreements

Pain intensity assessment scales are important in evaluating postoperative pain and guiding management. Different scales can be used for patients to self-report their pain, but research determining cut points between mild, moderate and severe pain has been limited to studies with < 1500 patients. We examined 13,017 simultaneous acute postoperative pain ratings from 913 patients taken at rest and on activity, between 4 h and 48 h following surgery using both a verbal rating scale (no, mild, moderate or severe pain) and 0-100 mm visual analogue scale. We determined the best cut points on the visual analogue scale between mild and moderate pain as 35 mm, and moderate and severe pain as 80 mm. These remained consistent for pain at rest and on activity, and over time. We also explored the presence of category disagreements, defined as patients verbally describing no or mild pain scored above the mild/moderate cut point on the visual analogue scale, and patients verbally describing moderate or severe pain scored below the mild/moderate cut point on the visual analogue scale. Using 30 and 60 mm cut points, 1533 observations (12%) showed a category disagreement and using 35 and 80 mm cut points, 1632 (13%) showed a category disagreement. Around 1 in 8 simultaneous pain scores implausibly disagreed, possibly resulting in incorrect pain reporting. The reasons are not known but low rates of literacy and numeracy may be contributing factors. Understanding these disagreements between pain scales is important for pain research and medical practice.

Recent advances in pain management based on nanoparticle technologies

BACKGROUND

Pain is a vital sense that indicates the risk of injury at a particular body part. Successful control of pain is the principal aspect in medical treatment. In recent years, the advances of nanotechnology in pain management have been remarkable. In this review, we focus on literature and published data that reveal various applications of nanotechnology in acute and chronic pain management.

METHODS

The presented content is based on information collected through pain management publications (227 articles up to April 2021) provided by Web of Science, PubMed, Scopus and Google Scholar services.

RESULTS

A comprehensive study of the articles revealed that nanotechnology-based drug delivery has provided acceptable results in pain control, limiting the side effects and increasing the efficacy of analgesic drugs. Besides the ability of nanotechnology to deliver drugs, sophisticated nanosystems have been designed to enhance imaging and diagnostics, which help in rapid diagnosis of diseases and have a significant impact on controlling pain. Furthermore, with the development of various tools, nanotechnology can accurately measure pain and use these measurements to display the efficiency of different interventions.

CONCLUSIONS

Nanotechnology has started a new era in the pain management and many promising results have been achieved in this regard. Nevertheless, there is still no substantial and adequate act of nanotechnology in this field. Therefore, efforts should be directed to broad investigations.

Recent Advances in Peripheral Opioid Receptor Therapeutics

PURPOSE OF REVIEW

Although opioids are excellent analgesics, they are associated with severe short- and long-term side effects that are especially concerning for the treatment of chronic pain. Peripherally acting opioid receptor agonists promise to mitigate the more serious centrally mediated side effects of opioids, and the goal of this paper is to identify and elaborate on recent advances in these peripheral opioid receptor therapeutics.

RECENT FINDINGS

Peripheral opioid receptor agonists are effective analgesics that at the same time circumvent the problem of centrally mediated opioid side effects by (1) preferentially targeting peripheral opioid receptors that are often the source of the pain and (2) their markedly diminished permeability or activity across the blood-brain barrier. Recent novel bottom-up approaches have been notable for the design of therapeutics that are either active only at inflamed tissue, as in the case of fentanyl-derived pH-sensitive opioid ligands, or too bulky or hydrophilic to cross the blood-brain barrier, as in the case of morphine covalently bound to hyperbranched polyglycerols. Recent innovations in peripheral opioid receptor therapeutics of pH-sensitive opioid ligands and limiting opioid permeability across the blood-brain barrier have had promising results in animal models. While this is grounds for optimism that some of these therapeutics will be efficacious in human subjects at a future date, each drug must undergo individualized testing for specific chronic pain syndromes to establish not only the nuances of each drug's therapeutic effect but also a comprehensive safety profile.

Variation in perioperative opioid use after total joint arthroplasty

Objective

We studied variation in perioperative opioid use after total joint arthroplasty with respect to patient and procedure characteristics in order to inform initiatives to optimize pain relief.

Methods

We recorded perioperative opioid consumption for a cohort of total joint arthroplasty patients to identify factors underlying variation in perioperative opioid use.

Results

Younger patient age, tobacco use, greater symptoms of depression, private insurance, and knee arthroplasty were associated with increased opioid consumption.

Conclusions

Awareness of the patient characteristics associated with increased perioperative opioid use can help inform implementation of targeted strategies for safe, optimal pain relief and satisfaction.

Nanotherapeutic-directed approaches to analgesia

The ongoing opioid crisis highlighted the need for non-steroidal anti-inflammatory drugs (NSAIDs), nonaddictive analgesics against pain, fever, and inflammation. However, NSAIDs may cause gastrointestinal and cardiovascular adverse effects. To avoid systemic toxicity and deliver drugs to diseased tissues, nanotechnology methods of NSAID encapsulation have been reported and some have reached clinical development. Currently, 57 micro- and nanodrugs are approved by the US FDA. Already approved nanoanalgesics have revealed superior efficacy or reduced toxicity compared with placebo or lower doses of systemically administered active comparators. In this review, the evidence for approval of the marketed nanodrugs will be discussed, with a focus on therapies for pain and inflammation. Nanomedicine remains an attractive field for the development of targeted analgesics.

Clinical Effectiveness of Liposomal Bupivacaine Administered by Infiltration or Peripheral Nerve Block to Treat Postoperative Pain

The authors provide a comprehensive summary of all randomized, controlled trials (n = 76) involving the clinical administration of liposomal bupivacaine (Exparel; Pacira Pharmaceuticals, USA) to control postoperative pain that are currently published. When infiltrated surgically and compared with unencapsulated bupivacaine or ropivacaine, only 11% of trials (4 of 36) reported a clinically relevant and statistically significant improvement in the primary outcome favoring liposomal bupivacaine. Ninety-two percent of trials (11 of 12) suggested a peripheral nerve block with unencapsulated bupivacaine provides superior analgesia to infiltrated liposomal bupivacaine. Results were mixed for the 16 trials comparing liposomal and unencapsulated bupivacaine, both within peripheral nerve blocks. Overall, of the trials deemed at high risk for bias, 84% (16 of 19) reported statistically significant differences for their primary outcome measure(s) compared with only 14% (4 of 28) of those with a low risk of bias. The preponderance of evidence fails to support the routine use of liposomal bupivacaine over standard local anesthetics.

Indwelling Urinary Catheter for Total Joint Arthroplasty Using Epidural Anesthesia

BACKGROUND

The objective of this study was to evaluate if not placing an indwelling urinary catheter leads to a higher potential for adverse genitourinary (GU) issues after total joint arthroplasty (TJA) under epidural anesthesia.

METHODS

Three hundred thirty-five consecutive patients who underwent primary TJA using epidural anesthesia were retrospectively reviewed. The initial 103 patients received a preoperative urinary catheter, which was maintained until the morning of postoperative day 1. The subsequent 232 patients did not receive a preoperative urinary catheter. Demographics, medical complications, GU complications, and length of stay were compared between groups.

RESULTS

Compared between catheter and noncatheter groups, there were no differences in demographics including age, gender, or laterality of surgery. There was a difference in type of surgery (total knee arthroplasty vs total hip arthroplasty) (P = .008). There was no difference in American Society of Anesthesiologists score, but with a difference in body mass index (P = .01). There were no differences in GU complications among patients with benign prostatic hyperplasia or prostate cancer. However, among patients with a history of prostate disorders (benign prostatic hyperplasia or prostate cancer), urinary tract infection rate was higher in catheter group (P = .023). Postoperative GU complications were associated with increased median age in years and increased average length of stay in days.

CONCLUSION

Patients undergoing TJA under epidural anesthesia demonstrate no increased risk of postoperative urological complications without the placement of preoperative indwelling urinary catheter. The routine use of preoperative catheters can be reconsidered for this mode of anesthesia.

LEVEL OF EVIDENCE

Level II, retrospective comparative study.

A New Approach to Deliver Anti-cancer Nanodrugs with Reduced Off-target Toxicities and Improved Efficiency by Temporarily Blunting the Reticuloendothelial System with Intralipid

We have developed a new strategy to temporarily blunt the reticuloendothelial system uptake of nanodrugs, a major challenge for nanodrug delivery and causing off-target toxicities, using an FDA approved nutrition supplement, Intralipid. We have tested our methodology in rats using an experimental platinum-containing anti-cancer nanodrug and three FDA approved nanodrugs, Abraxane, Marqibo, and Onivyde, to determine their toxicities in liver, spleen, and kidney, with and without the addition of Intralipid. Our method illustrates its potentials to deliver nanodrugs with an increase in the bioavailability and a decrease in toxicities. Our study shows that Intralipid treatment exhibits no harmful effect on tumor growing and no negative effect on the anti-tumor efficacy of the platinum-containing nanodrug, as well as animal survival rate in a HT-29 xenograft mouse model. Our methodology could also be a valuable complement/supplement to the “stealth” strategies. Our approach is a general one applicable to any approved and in-development nanodrugs without additional modification of the nanodrugs, thus facilitating its translation to clinical settings.

Adjuvants to local anesthetics: Current understanding and future trends

Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by its duration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids (dexamethasone), anti-inflammatory agents (parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action (tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability (liposomal, microspheres and cyclodextrin systems) and further studies with other drugs (adenosine, neuromuscular blockers, dextrans).

Intrathecal Morphine Versus Extended-Release Epidural Morphine for Postoperative Pain Control in Pediatric Patients Undergoing Posterior Spinal Fusion

BACKGROUND

Posterior spinal fusion for scoliosis is one of the most painful elective pediatric surgeries. Good postoperative pain control allows early ambulation and return of ability to tolerate oral intake. Options for analgesia in this patient population are suboptimal. We hypothesized that extended-release epidural morphine (EREM) would provide better pain control and less adverse effects compared to intrathecal (IT) morphine.

METHODS

The primary outcome was total IV morphine consumption during 0-48 hours postoperatively. Secondary outcomes included time until first patient-controlled analgesia (PCA) demand, pain scores, and adverse opioid effects. After institutional review board approval, 71 subjects undergoing posterior spinal fusion for idiopathic scoliosis completed the study. The subjects were randomly allocated to 7.5 μg/kg IT morphine or 150 μg/kg EREM. The final IT morphine and EREM groups contained 37 and 34 subjects, respectively. Postoperative pain was treated with morphine PCA, ketorolac, oral oxycodone, and acetaminophen. Morphine consumption, pain scores, nausea and vomiting, pruritus, and respiratory depression were measured every 4 hours. Parents completed a caregiver questionnaire about their child's pain control regimen after the first postoperative day.

RESULTS

There was no difference in total morphine consumption over the first 48 hours between subjects in the EREM and IT morphine groups: median (range) 42.2 (5.5-123.0) and 34.0 (4.5-128.8) mg, respectively (P = .27). EREM and IT morphine groups had no difference in time until first PCA demand. Pain scores were no different between the groups from 8 to 24 hours after surgery. Compared to IT morphine, EREM subjects had lower pain scores from 28 to 36 hours after surgery. The reported incidence of pruritus was lower in the EREM subjects.

CONCLUSIONS

There was no difference in total morphine consumption or time until first PCA demand between the EREM and IT morphine groups. EREM provides a longer duration of analgesia after posterior spinal fusion for scoliosis and may be associated with less opioid-induced pruritus.

Postoperative pain management

Postoperative pain is a very important issue for several patients. Indifferent of the surgery type or method, pain management is very necessary. The relief from suffering leads to early mobilization, less hospital stay, reduced hospital costs, and increased patient satisfaction. An individual approach should be applied for pain control, rather than a fix dose or drugs. Additionally, medical, psychological, and physical condition, age, level of fear or anxiety, surgical procedure, personal preference, and response to agents given should be taken into account. The major goal in the management of postoperative pain is minimizing the dose of medications to lessen side effects while still providing adequate analgesia. Again a multidisciplinary team approach should be pursued planning and formulating a plan for pain relief, particularly in complicated patients, such as those who have medical comorbidities. These patients might appear increase for analgesia-related complications or side effects.

Pain care for patients with epidermolysis bullosa: best care practice guidelines

BACKGROUND

Inherited epidermolysis bullosa (EB) comprises a group of rare disorders that have multi-system effects and patients present with a number of both acute and chronic pain care needs. Effects on quality of life are substantial. Pain and itching are burdensome daily problems. Experience with, and knowledge of, the best pain and itch care for these patients is minimal. Evidence-based best care practice guidelines are needed to establish a base of knowledge and practice for practitioners of many disciplines to improve the quality of life for both adult and pediatric patients with EB.

METHODS

The process was begun at the request of Dystrophic Epidermolysis Bullosa Research Association International (DEBRA International), an organization dedicated to improvement of care, research and dissemination of knowledge for EB patients worldwide. An international panel of experts in pain and palliative care who have extensive experience caring for patients with EB was assembled. Literature was reviewed and systematically evaluated. For areas of care without direct evidence, clinically relevant literature was assessed, and rounds of consensus building were conducted. The process involved a face-to-face consensus meeting that involved a family representative and methodologist, as well as the panel of clinical experts. During development, EB family input was obtained and the document was reviewed by a wide variety of experts representing several disciplines related to the care of patients with EB.

RESULTS

The first evidence-based care guidelines for the care of pain in EB were produced. The guidelines are clinically relevant for care of patients of all subtypes and ages, and apply to practitioners of all disciplines involved in the care of patients with EB. When the evidence suggests that the diagnosis or treatment of painful conditions differs between adults and children, it will be so noted.

CONCLUSIONS

Evidence-based care guidelines are a means of standardizing optimal care for EB patients, whose disease is often times horrific in its effects on quality of life, and whose care is resource-intensive and difficult. The guideline development process also highlighted areas for research in order to improve further the evidence base for future care.

Enhancing the Enhanced Recovery Program in Colorectal Surgery - Use of Extended-Release Epidural Morphine (DepoDur®)

Purpose

DepoDur® is a single-dose extended-release morphine injection into the epidural space. It is not commonly used, but has many advantages over traditional analgesic regimens. We analyzed a number of these advantages in our case series in the context of the colorectal enhanced recovery program (ERP) and aimed to show that the ERP could be further enhanced by using DepoDur®.

Methods

We conducted a prospective audit of all patients undergoing open and laparoscopic colorectal procedures where DepoDur® was used between July 2010 and April 2012. Validated pain scores were used, and primary outcome measures were resting and dynamic pain, mobilization, and need for additional analgesia.

Results

Two hundred eighty patients were included in the case series. Good pain control was seen at 24 and 48 hours. Eighty-one percent of the patients required simple analgesia alone at 24 hours, and 62% required simple analgesia (paracetamol +/- nonsteroidal anti-inflammatory drugs) alone at 48 hours. Only a minority required additional oramorph and patient-controlled analgesia at 24 and 48 hours (19% at 24 hours and 38% at 48 hours). Seventy-nine percent of the patients were mobilized at 24 hours, and 88% of the patients were mobilized at 48 hours.

Conclusion

DepoDur® is an effective alternative to conventional pain management techniques and may have a role in further enhancing the ERP.

The use of lipid-based nanocarriers for targeted pain therapies

Sustained delivery of analgesic agents at target sites remains a critical issue for effective pain management. The use of nanocarriers has been reported to facilitate effective delivery of these agents to target sites while minimizing systemic toxicity. These include the use of biodegradable liposomal or polymeric carriers. Of these, liposomes present as an attractive delivery system due to their flexible physicochemical properties which allow easy manipulation in order to address different delivery considerations. Their favorable toxicity profiles and ease of large scale production also make their clinical use feasible. In this review, we will discuss the concept of using liposomes as a drug delivery carrier, their in vitro characteristics as well as in vivo behavior. Current advances in the targeted liposomal delivery of analgesic agents and their impacts on the field of pain management will be presented.

Randomized trial demonstrates that extended-release epidural morphine may provide safe pain control for lumbar surgery patients

Background:

Safe and effective postoperative pain control remains an issue in complex spine surgery. Spinal narcotics have been used for decades but have not become commonplace because of safety or re-dosing concerns. An extended release epidural morphine (EREM) preparation has been used successfully in obstetric, abdominal, thoracic, and extremity surgery done with epidural anesthesia. This has not been studied in open spinal surgery.

Methods:

Ninety-eight patients having complex posterior lumbar surgery were enrolled in a partially randomized clinical trial (PRCT) of low to moderate doses of EREM. Surgery included levels from L3 to S1 with procedures involving combinations of decompression, instrumented arthrodesis, and interbody grafting. The patients were randomized to receive either 10 or 15 mg of EREM through an epidural catheter placed under direct vision at the conclusion of surgery. Multiple safety measures were employed to prevent or detect respiratory depression. Postoperative pain scores, narcotic utilization, and adverse events were recorded.

Results:

There were no significant differences between the two groups as to supplemental narcotic requirements, pain scores, or adverse events. There were no cases of respiratory depression. The epidural narcotic effect persisted from 3 to 36 hours after the injection.

Conclusion:

By utilizing appropriate safety measures, EREM can be used safely for postoperative pain control in lumbar surgery patients. As there was no apparent advantage to the use of 15 mg, the lower 10 mg dose should be used.

Drug therapy for preventing post-dural puncture headache

BACKGROUND

Post-dural (post-lumbar or post-spinal) puncture headache (PDPH) is one of the most common complications of diagnostic, therapeutic or inadvertent lumbar punctures. Many drug options have been used to prevent headache in clinical practice and have also been tested in some clinical studies, but there are still some uncertainties about their clinical effectiveness.

OBJECTIVES

To assess the effectiveness and safety of drugs for preventing PDPH in adults and children.

SEARCH METHODS

The search strategy included the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2012, Issue 5), MEDLINE (from 1950 to May 2012), EMBASE (from 1980 to May 2012) and CINAHL (from 1982 to June 2012). There was no language restriction.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that assessed the effectiveness of any drug used for preventing PDPH.

DATA COLLECTION AND ANALYSIS

Review authors independently selected studies, assessed risks of bias and extracted data. We estimated risk ratios (RR) for dichotomous data and mean differences (MD) for continuous outcomes. We calculated a 95% confidence interval (CI) for each RR and MD. We did not undertake meta-analysis because participants' characteristics or assessed doses of drugs were too different in the included studies. We performed an intention-to-treat (ITT) analysis.

MAIN RESULTS

We included 10 RCTs (1611 participants) in this review with a majority of women (72%), mostly parturients (women in labour) (913), after a lumbar puncture for regional anaesthesia. Drugs assessed were epidural and spinal morphine, spinal fentanyl, oral caffeine, rectal indomethacin, intravenous cosyntropin, intravenous aminophylline and intravenous dexamethasone.All the included RCTs reported data on the primary outcome, i.e. the number of participants affected by PDPH of any severity after a lumbar puncture. Epidural morphine and intravenous cosyntropin reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to placebo. Also, intravenous aminophylline reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to no intervention, while intravenous dexamethasone increased it. Spinal morphine increased the number of participants affected by pruritus when compared to placebo, and epidural morphine increased the number of participants affected by nausea and vomiting when compared to placebo. Oral caffeine increased the number of participants affected by insomnia when compared to placebo.The remainder of the interventions analysed did not show any relevant effect for any of the outcomes.None of the included RCTs reported the number of days that patients stayed in hospital.

AUTHORS' CONCLUSIONS

Morphine and cosyntropin have shown effectiveness for reducing the number of participants affected by PDPH of any severity after a lumbar puncture, when compared to placebo, especially in patients with high risk of PDPH, such as obstetric patients who have had an inadvertent dural puncture. Aminophylline also reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to no intervention in patients undergoing elective caesarean section. Dexamethasone increased the risk of PDPH, after spinal anaesthesia for caesarean section, when compared to placebo. Morphine also increased the number of participants affected by adverse events (pruritus and nausea and vomiting)There is a lack of conclusive evidence for the other drugs assessed (fentanyl, caffeine, indomethacin and dexamethasone).These conclusions should be interpreted with caution, owing to the lack of information, to allow correct appraisal of risk of bias and the small sample sizes of studies.

The analgesic effect of intrathecal dexmedetomidine or clonidine, with bupivacaine, in trauma patients undergoing lower limb surgery: a randomised, double-blind study

This randomised, double-blind study was designed to compare the duration of analgesia and adverse effects following intrathecal administration of dexmedetomidine or clonidine, both with bupivacaine, in trauma patients. Ninety adult trauma patients of American Society of Anesthesiologists physical status I-II, scheduled for lower limb surgery under subarachnoid block, were randomly allocated to one of three groups. All groups received hyperbaric bupivacaine 0.5% 3 ml, to which was added saline 0.5 ml (Group B): clonidine 50 µg (Group C) or dexmedetomidine 5 µg (Group D). The onset and duration of sensory and motor blockade, severity of postoperative pain, time to first rescue analgesia and total analgesic requirement for 24 hours were noted. There was no significant difference in the onset time of the block but the duration of sensory and motor blockade was prolonged in Groups C and D, compared with Group B. The time to analgesia was significantly prolonged in Group D (824±244 minutes) compared with Group C (678±178 minutes; P=0.01), the latter being longer than Group B (406±119 minutes; P=0.0001). Postoperative pain scores were lower in Groups C and D compared with group b. The requirement for rescue analgesia during the first 24 postoperative hours was significantly less in Groups C and D as compared to Group B (P=0.0001), but comparable between Groups C and D (P=0.203). In conclusion, dexmedetomidine 5 µg added to intrathecal bupivacaine 15 mg produces longer postoperative analgesia than clonidine 50 µg among trauma patients undergoing lower limb surgery.

Recent advances in the pharmaceutical management of pain

Pain is an unpleasant sensory and emotional experience for patients. Management of pain is the most frequent issue encountered by clinicians and treatment is usually with pharmacological therapy. This review discusses recent pharmaceutical advances in pain management with respect to new modes of analgesic delivery, as well as new analgesic agents and adjuvants that are currently being investigated for their analgesic properties. New modes of administration include transdermal delivery in the form of skin patches, transmucosal delivery, inhalational administration, various patient-controlled devices and extended-release analgesic formulations. Up-to-date research is presented on classical analgesics, such as opioids, anti-inflammatory agents, including cyclo-oxygenase-2 inhibitors and paracetamol (acetaminophen), local anesthetics and ketamine. In addition, newer agents such as antidepressants and antiepileptic drugs as well as medicinal cannabinoids are discussed. As our understanding of the multiple pain pathways involved in the pathogenesis of pain expands, further compounds with analgesic properties will be developed.

Neuraxial anesthesia and bladder dysfunction in the perioperative period: a systematic review

PURPOSE

Urinary retention requiring catheterization carries the risk of infection. Neuraxial anesthesia causes transient impairment of bladder function ranging from delayed initiation of micturition to frank urinary retention. We undertook a review of the literature to determine the elements of neuraxial anesthesia and analgesia that prolong bladder dysfunction and increase the incidence of urinary retention.

METHODS

We performed a systematic search of the PubMed, MEDLINE, and EMBASE databases (from January 1980 to January 2011) to identify studies where neuraxial anesthesia and/or analgesia were employed and at least one of the following outcomes was reported: urinary retention, time to micturition, or post void residual. We included randomized controlled trials and observational studies published in the English language and we excluded case reports. The randomized trials were graded according to the Jadad score.

PRINCIPAL FINDINGS

Our search yielded 94 studies, and in 16 of these studies, the authors reported time to micturition after intrathecal anesthesia of varying local anesthetics and doses. Intrathecal injections were performed in 41 of these studies, epidural anesthesia/analgesia was used in 39 studies, and five studies involved both the intrathecal and epidural routes. Meta-analysis was not possible because of the heterogeneity of interventions and reported outcomes. The duration of detrusor dysfunction after intrathecal anesthesia is correlated with local anesthetic dose and potency. The incidence of urinary retention displays a similar trend and is further increased by the presence of neuraxial opioids, particularly long-acting variants. Urinary tract infection secondary to catheterization occurred rarely.

CONCLUSIONS

Neuraxial anesthesia/analgesia results in transient detrusor dysfunction. The duration of dysfunction depends on the potency and dose of medication used; however, it does not appear to result in significant morbidity.

Pharmacokinetics and behavioral effects of liposomal hydromorphone suitable for perioperative use in rhesus macaques

INTRODUCTION

This study aims to evaluate the pharmacokinetic, behavioral, and motor effects of a liposomal preparation of hydromorphone hydrochloride (LE-hydro) in rhesus monkeys. We administered either 2 mg/kg of LE-hydro (n = 8) subcutaneous (s.c.) or 0.1 mg/kg of standard pharmaceutical hydromorphone HCl (hydro) preparation either intravenous (i.v.; n = 4) or s.c. (n = 5).

MATERIALS AND METHODS

Serial blood samples were drawn after injection and analyzed for serum hydro concentration by liquid chromatography/mass spectrometry. Following s.c. injection of 0.1 mg/kg hydro or 2 mg/kg LE-hydro, behavioral evaluations were conducted in groups of rhesus monkeys (n = 10/group) in the presence of a compatible stimulus animal and motor skills were also evaluated (n = 10/group). The motor skills test consisted of removing a food reward (carrot ring) from either a straight peg (simple task) or a curved peg (difficult task).

RESULTS

LE-hydro (MRT(0-INF) = 105.9 h) demonstrated extended-release pharmacokinetics compared to hydro when administered by either i.v. (MRT(0-INF) =1.1 h) or s.c. (MRT(0-INF) =1.3 h) routes. Hydro did not affect motor performance of the simpler task, but the monkeys' performance deteriorated on the more difficult task at 0.5 and 1 h after injection. LE-hydro had no effect on motor skills in either the simpler or more difficult task.

CONCLUSIONS

The results of these studies indicate that LE-hydro has a pharmacokinetic and behavioral side effects profile consistent with an analgesic that could be tested for surgical use in animals. Our studies also expand the use of rhesus monkeys as a translational behavioral pharmacodynamics model for testing extended-release opioid medication.

Treatment of acute postoperative pain

Although postoperative pain remains incompletely controlled in some settings, increased understanding of its mechanisms and the development of several therapeutic approaches have substantially improved pain control in past years. Advances in our understanding of the process of nociception have led to insight into gene-based pain therapy, the development of acute opioid-induced hyperalgesia, and persistent postsurgical pain. Use of specific analgesic techniques such as regional analgesia could improve patient outcomes. We also examine the development of new analgesic agents and treatment modalities and regimens for acute postoperative pain.

Implications of opioid analgesia for medically complicated patients

Opioid analgesics have an established role in the management of postoperative pain and cancer pain, and are gaining acceptance for the management of moderate to severe chronic noncancer pain, most notably chronic low back pain and osteoarthritis, that does not respond to other interventions. Many patients with chronic pain have co-morbid medical conditions that may complicate opioid therapy. Selecting the appropriate opioid requires knowledge of how individual opioids differ with respect to metabolism and interaction with concurrent medications, as well as the reasons why specific medical conditions may influence their efficacy and tolerability. Polypharmacy is a common complicating condition in the elderly and in patients with psychiatric illness, cancer, cardiovascular disease, diabetes mellitus or other chronic illnesses. Polypharmacy, though often necessary for patients with multiple medical conditions, also multiplies the risk of drug interactions. Pharmacokinetic drug interactions can increase or reduce exposure to the opioid or concurrent medications, reducing efficacy and/or tolerability and increasing toxicity. Pharmacodynamic interactions can enhance the depressive effects of opioids, compromising safety. Patients with impaired renal or hepatic function may have difficulty clearing or metabolizing opioids and concurrent medications, leading to increased risk of adverse events. Patients with cardiovascular, cerebrovascular or respiratory disease (including smokers of >/=2 packs/day with no other diagnosis) may be more susceptible to respiratory depression, bradycardia and hypotension with any opioid, and a few specific opioids pose additional risks. Patients with cerebrovascular disease, dementia, brain injury or psychiatric illness are more susceptible to opioid effects on the CNS, which can include euphoria, cognitive impairment and sedation. Appropriate opioid selection may mitigate these effects. Even in older patients, addiction, abuse and misdirection of prescribed opioids are of concern. Higher risk exists for patients with psychiatric illness, history of substance abuse, and identifiable substance abuse risk factors. Screening for abuse potential and vigilant patient monitoring should be routine. Opioids differ in their ability to produce euphoria, based on opioid receptor agonism, but substance abusers may be more influenced by availability, familiarity and cost factors. Consequently, opioid selection has limited influence on abuse potential but can facilitate ease of monitoring. This review provides an overview of opioid use in medically complicated patients and recommendations on how to optimize analgesia while avoiding adverse events and drug interactions in the clinical setting. Articles cited in this review were identified via a search of EMBASE and PubMed. Articles selected for inclusion discussed characteristics of specific opioids and general physiological aspects of opioid therapy in important patient populations.

Pain management in total joint arthroplasty: a historical review

Patients undergoing total hip and knee arthroplasty experience substantial and sustained postoperative pain. Inadequate analgesia may impede recovery and delay hospital discharge. Traditionally, postoperative analgesia following arthroplasty was provided by intravenous patient-controlled analgesia or epidural analgesia, but each technique has distinct advantages and disadvantages. Recently, peripheral nerve blockade of the lumbosacral plexus has emerged as an alternative analgesic approach. An increasing number of studies have reported multimodal analgesia featuring unilateral peripheral block provide pain relief and functional outcomes similar to that of continuous epidural and superior to systemic analgesia but with fewer side effects. This review discusses the indications, benefits, and side effects associated with conventional and innovative analgesic approaches to facilitate rehabilitation and improve outcome following total joint arthroplasty.

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

BACKGROUND

This study retrospectively compared the continuous epidural infusion of morphine with a single epidural injection of extended-release morphine for postoperative pain control after arthroplasty.

METHODS

Medical records were reviewed for subjects who had total knee or hip arthroplasty (THA) under spinal anesthesia and received either a continuous epidural infusion of morphine (Group EPID; n = 101) or an extended-release epidural morphine (Group EREM; n = 109) for postoperative pain. Data were collected for three postoperative days (POD) on: pain scores; supplemental opioids; medications for respiratory depression, nausea, and pruritus, and distance ambulated during physical therapy.

RESULTS

Pain scores were similar until subjects were transitioned to another analgesic approach on POD 2; after that time, pain scores increased in Group EPID, although they decreased in Group EREM. Supplemental opioids were used more on POD1 in Group EREM than in Group EPID, although time to first opioid and total daily morphine equivalents were similar. Naloxone and antiemetics, not antipruritics, were used more in Group EREM. Distance ambulated after THA was greater in Group EREM than in Group EPID.

CONCLUSIONS

These results suggest that EREM is associated with better postoperative ambulation and analgesia during the transition to oral or intravenous analgesics, although a higher incidence of side-effects was evident.

A comparison of change in the 0-10 numeric rating scale to a pain relief scale and global medication performance scale in a short-term clinical trial of breakthrough pain intensity

BACKGROUND

Pain intensity is commonly reported using a 0-10 Numeric Rating Scale in pain clinical trials. Analysis of the change on the Pain Intensity Numerical Rating Scale as a proportion has most consistently correlated with clinically important differences reported on the patient's global impression of change. The correlation of data from patients with breakthrough pain with a Pain Relief Scale and a different global outcome measures will extend our understanding of these measures.

METHODS

Data were obtained from the open titration phase of a multiple crossover, randomized, double-blind clinical trial comparing oral transmucosal fentanyl citrate with immediate-release oral morphine sulfate for the treatment of cancer-related breakthrough pain. Raw and percentage changes in the pain intensity scores from 1,307 episodes of pain in 134 oral transmucosal fentanyl citrate-naïve patients were correlated with the clinically relevant secondary outcomes of Pain Relief Verbal Response Scale and the global medication performance scale. The changes in raw and percentage change were assessed over time and compared with the ordinal Pain Relief Verbal Response Scale and Global Medication Performance Scale.

RESULTS

The P value of the interaction between the raw pain intensity difference was significant (P = 0.034) for four 15-min time periods but not for the percentage pain intensity difference score (P = 0.26). We found similar results in comparison with the ordinal Pain Relief Verbal Response Scale (P = 0.0048 and P = 0.36 respectively) and global medication performance categories (P = 0.048 and P = 0.45, respectively).

CONCLUSION

The change in pain intensity in breakthrough pain was more consistent over time and when compared with both the Pain Relief Verbal Response Scale and the Global Medication Performance Scale when the percentage change is used rather than raw pain intensity difference.

Lessons learned with extended-release epidural morphine after total hip arthroplasty

An extended-release epidural morphine (EREM) has been introduced to improve postoperative pain management. Studies have shown the effectiveness of this agent in providing better pain control and patient satisfaction for patients undergoing total joint arthroplasty. We evaluated postoperative pain relief by comparing average daily pain scores and opioid use with those of the control group. Safety was measured by comparing the occurrence of postoperative complications, nausea and vomiting, pruritus, and respiratory depression between the two groups. Between February 2006 and March 2008, we selected 203 patients to receive EREM for THA. These patients were matched in a 2:1 ratio with patients undergoing THA and receiving spinal anesthesia. We retrospectively reviewed all major and minor postoperative complications from a prospective database. Patients receiving EREM had lower pain scores than patients not receiving EREM on Postoperative Day 1 (POD 1) but not POD 2, or POD 3. Patients receiving EREM experienced a slightly higher incidence of pulmonary embolism and supraventricular tachycardia. Patients receiving EREM also experienced more nausea and vomiting and pruritus. We found EREM provided better pain relief on POD 1 at the expense of a slightly higher incidence of side effects compared with spinal anesthesia alone.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Analysis of individual patient data from clinical trials: epidural morphine for postoperative pain

BACKGROUND

Individual patient information from clinical trials is infrequently available, but can provide insights for clinical trials and practice.

METHODS

We analysed individual patient information from five randomized trials (913 patients) of i.v. patient-controlled analgesia (IVPCA) plus epidural placebo, morphine sulphate (MS) 5 mg, or extended-release epidural morphine (EREM; DepoDur) at doses of 5-30 mg, to explore effects of a range of epidural morphine doses. Pain and opioid requirement on first and second postoperative days, dose-response, clinically relevant comparisons of IVPCA without epidural morphine, 5 mg MS, and 10 mg EREM, and relationship between patient rating and other measures were described.

RESULTS

There were three strong findings. Epidural morphine resulted in greater patient satisfaction, despite higher rates of adverse events. Those describing their analgesic medication as 'very good' or 'excellent' used IVPCA opioid less and had pain scores significantly below the global mean, whereas those describing their medication as 'poor' or 'fair' had pain scores significantly above the mean. Epidural morphine meant less need for postoperative IVPCA opioid than epidural placebo. The therapeutic gain with EREM was lower pain scores with less IVPCA opioid. Moderate or severe pruritus was more common with IVPCA plus epidural morphine, whatever the formulation, compared with IVPCA plus placebo.

CONCLUSIONS

Analysis of individual patient data from high-quality clinical trials provides important insights into characteristics of new agents not immediately apparent from original trials, and also informing clinical practice. Prophylactic epidural morphine provides a better patient experience than IVPCA alone.

Extended-release epidural morphine (DepoDur) following epidural bupivacaine in patients undergoing lower abdominal surgery: a randomized controlled pharmacokinetic study

BACKGROUND AND OBJECTIVES

The primary objective was to compare the serum pharmacokinetic profile of a single dose of extended-release epidural morphine (EREM) administered alone versus 15 to 60 mins after an analgesic epidural dose of bupivacaine.

METHODS

This multicenter study enrolled 144 patients, 18 years or older, with scheduled lower abdominal surgery under general anesthesia. Patients were randomly assigned to a single 15-mg dose of EREM; the same dose administered 15, 30, or 60 mins after epidural bupivacaine (20 mL 0.25%); or epidural placebo (normal saline) administered 15, 30, or 60 mins after bupivacaine. Postoperatively, fentanyl patient-controlled analgesia was offered for breakthrough pain. Multiple serum samples were analyzed for morphine and morphine metabolites. Safety and efficacy were assessed.

RESULTS

The mean maximum serum concentration and area under the concentration-time curve for morphine and metabolites were not significantly different when EREM was administered alone versus 15, 30, or 60 mins after bupivacaine. Median time to maximum serum concentration and median apparent terminal elimination half-life were also comparable. Total fentanyl patient-controlled analgesia consumption was comparable among all EREM groups (with/without prior bupivacaine) but significantly (P < 0.05) lower compared with the bupivacaine + placebo group. Nausea, vomiting, and dizziness were consistently more frequent in groups receiving EREM after bupivacaine versus EREM alone.

CONCLUSIONS

The pharmacokinetic and efficacy profiles of a single 15-mg dose of EREM were not significantly altered when administered 15, 30, or 60 mins after an analgesic epidural dose of bupivacaine.

Does regional anaesthesia improve outcome after total hip arthroplasty? A systematic review

Total hip arthroplasty (THA) is amenable to a variety of regional anaesthesia (RA) techniques that may improve patient outcome. We sought to answer whether RA decreased mortality, cardiovascular morbidity, deep venous thrombosis (DVT) and pulmonary embolism (PE), blood loss, duration of surgery, pain, opioid-related adverse effects, cognitive defects, and length of stay. We also questioned whether RA improved rehabilitation. To do so, we performed a systematic review of the contemporary literature to compare general anaesthesia (GA) and RA and also systemic and regional analgesia for THA. To reflect contemporary surgical and anaesthetic practice, only randomized controlled trials (RCTs) from 1990 onward were included. We identified 18 studies involving 1239 patients. Only two of the 18 trials were of Level I quality. There is insufficient evidence from RCTs alone to conclude if anaesthetic technique influenced mortality, cardiovascular morbidity, or the incidence of DVT and PE when using thromboprophylaxis. Blood loss may be reduced in patients receiving RA rather than GA for THA. Our review suggests that there is no difference in duration of surgery in patients who receive GA or RA. Compared with systemic analgesia, regional analgesia can reduce postoperative pain, morphine consumption, and nausea and vomiting. Length of stay is not reduced and rehabilitation does not appear to be facilitated by RA or analgesia for THA.

Multimodal pain management after total hip and knee arthroplasty at the Ranawat Orthopaedic Center

Improvements in pain management techniques in the last decade have had a major impact on the practice of total hip and knee arthroplasty (THA and TKA). Although there are a number of treatment options for postoperative pain, a gold standard has not been established. However, there appears to be a shift towards multimodal approaches using regional anesthesia to minimize narcotic consumption and to avoid narcotic-related side effects. Over the last 10 years, we have used intravenous patient-controlled analgesia (PCA), femoral nerve block (FNB), and continuous epidural infusions for 24 and 48 hours with and without FNB. Unfortunately, all of these techniques had shortcomings, not the least of which was suboptimal pain control and unwanted side effects. Our practice has currently evolved to using a multimodal protocol that emphasizes local periarticular injections while minimizing the use of parenteral narcotics. Multimodal protocols after THA and TKA have been a substantial advance; they provide better pain control and patient satisfaction, lower overall narcotic consumption, reduce hospital stay, and improve function while minimizing complications. Although no pain protocol is ideal, it is clear that patients should have optimum pain control after TKA and THA for enhanced satisfaction and function.

LEVEL OF EVIDENCE

Level V, expert opinion. See the Guidelines for Authors for a complete description of levels of evidence.

Pharmacokinetics and behavioral effects of an extended-release, liposome-encapsulated preparation of oxymorphone in rhesus macaques

The objectives of the study were to determine the pharmacokinetics of oxymorphone (oxy) and of ammonium sulfate-loaded, liposome-encapsulated oxymorphone (LE-ASG oxy) and to evaluate the behavioral effects of both opioid preparations by using ethographic evaluation specific to rhesus monkeys. Rhesus monkeys (n = 8) were injected with 2.0 mg/kg LE-ASG oxy s.c.. Blood samples were collected at serial time points up to 144 h in six monkeys and up to 456 h in two monkeys. Separate groups of monkeys were injected with 0.1 mg/kg oxy s.c. (n = 4) or i.v. (n = 5). Blood samples were collected at serial time points up to 24 h after injection. Pharmacokinetic parameters were calculated by using commercially available software. Behavior was recorded in a different group of 10 monkeys administered LE-ASG oxy (2.0 mg/kg s.c.) or oxy (0.1 mg/kg s.c.) on separate occasions. Behavioral evaluations were made at serial time points while monkeys were in an extended cage with a compatible stimulus animal. Oxymorphone was rapidly eliminated from the serum in the oxy group. Measurable drug was present in serum for up to 4 h after oxy was administered subcutaneously or intravenously. LE-ASG oxy was present in serum in measurable concentrations for more than 2 weeks. Neither oxy nor LE-ASG oxy produced observable sedation. LE-ASG oxy decreased some environmentally directed behaviors, but this drug formulation increased watchfulness, decreased self-directed and elimination behaviors, increased nonspecific social contact, and decreased threat behaviors. LE-ASG oxy persisted for an extended period in rhesus monkey serum and produced behavioral changes consistent with this opioid.

Extended-release epidural morphine (DepoDur): review and safety analysis

Extended-release epidural morphine (EREM) provides effective postoperative analgesia for 48 h following injection. It is administered as a single bolus into the lumbar epidural space, and is indicated for lower abdominal and lower extremity surgery associated with moderate-to-severe pain. While its efficacy has been well documented in randomized controlled trials, the safety and clinically appropriate dosing are less well defined. A meta-analysis approach was used to assess the adverse effects of EREM (n = 801) in comparison with intravenous opioids and standard epidural morphine. EREM 15 mg or greater was associated with a trend towards a higher incidence of hypoventilation (odds ratio: 0.48; 95% confidence interval [CI]: 0.21-1.09; p = 0.081; number-needed-to-treat [NNT] = 14) compared with placebo. The incidence of pruritus was significantly higher for all EREM doses compared with both placebo (p = 0.004) and standard epidural morphine (p = 0.03). Vomiting was also increased with EREM 15 mg or greater compared with placebo (odds ratio: 0.40; 95% CI: 0.18-0.89; p = 0.02; NNT = 5). A multimodal analgesic regime is recommended to permit the use of lower EREM doses, thus reducing the risk for adverse effects including respiratory depression. Prophylactic time-contingent antiemetics are also recommended when EREM is used.

Cancer pain and analgesia

Pain ranges in prevalence from 14-100% among cancer patients and occurs in 50-70% of those in active treatment. Cancer pain may result from direct invasion of tumor into nerves, bones, soft tissue, ligaments, and fascia, and may induce visceral pain through distension and obstruction. Cancer pain is multifaceted. Clinicians may describe cancer pain as acute, chronic, nociceptive (somatic), visceral, or neuropathic. Despite implementation of the WHO guidelines, reports of undertreatment of cancer pain persist in various clinical settings and in spite of decades of work to reduce unnecessary discomfort. Substantial obstacles to adequate pain relief with opioids include specific concerns of patients themselves, their family members, physicians, nurses, and the healthcare system. The WHO analgesic ladder serves as the mainstay of treatment for the relief of cancer pain in concert with tumoricidal, surgical, interventional, radiotherapeutic, psychological, and rehabilitative modalities. This multidimensional approach offers the greatest potential for maximizing analgesia and minimizing adverse effects. Primary therapies are directed at the source of the cancer pain and may enhance a patient's function, longevity, and comfort. Adjuvant therapies include nonopioids that confer analgesic effects in certain medical conditions but primarily treat conditions that do not involve pain. Nonopioid medications (over-the-counter agents) are useful in the management of mild to moderate pain, and their continuation through step 3 of the WHO ladder is an option after weighing a drug's risks and benefits in individual patients. Symptomatic treatment of severe cancer pain should begin with an opioid, regardless of the mechanism of the pain. They are very effective analgesics, titrate easily, and offer a favorable risk/benefit ratio. Cancer pain remains inadequately controlled despite the diagnostic and therapeutic means of ensuring that patients feel comfortable during their illness. Therefore, all practitioners need to make control of cancer pain a professional duty, even if they can only use the most basic and least expensive analgesic medications, such as morphine, codeine, and acetaminophen, to reduce human suffering.